Camera Preview, version II

In the exercise "Camera Preview on SurfaceView", I show how to using Android's camera preview on a SurfaceView. The preview is set Start/Stop using buttons, it's not a good approach I think. In this exercise, it is re-arranged to handle the preview in SurfaceHolder.Callback methods: surfaceCreated(), surfaceChanged() and surfaceDestroyed().



Remember to grant permission to access Camera AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.exercise.AndroidCamera"
     android:versionCode="1"
     android:versionName="1.0">
   <application android:icon="@drawable/icon" android:label="@string/app_name">
       <activity android:name=".AndroidCamera"
                 android:label="@string/app_name">
           <intent-filter>
               <action android:name="android.intent.action.MAIN" />
               <category android:name="android.intent.category.LAUNCHER" />
           </intent-filter>
       </activity>

   </application>
   <uses-sdk android:minSdkVersion="4" />
   <uses-permission android:name="android.permission.CAMERA"></uses-permission>
</manifest>

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  >
<SurfaceView
  android:id="@+id/camerapreview"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  />
</LinearLayout>

AndroidCamera.java

package com.exercise.AndroidCamera;

import java.io.IOException;

import android.app.Activity;
import android.content.pm.ActivityInfo;
import android.graphics.PixelFormat;
import android.hardware.Camera;
import android.os.Bundle;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

public class AndroidCamera extends Activity implements SurfaceHolder.Callback{

Camera camera;
SurfaceView surfaceView;
SurfaceHolder surfaceHolder;
boolean previewing = false;;

  /** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.main);
      setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
    
      getWindow().setFormat(PixelFormat.UNKNOWN);
      surfaceView = (SurfaceView)findViewById(R.id.camerapreview);
      surfaceHolder = surfaceView.getHolder();
      surfaceHolder.addCallback(this);
      surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
  }



@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
 int height) {
// TODO Auto-generated method stub
if(previewing){
 camera.stopPreview();
 previewing = false;
}

if (camera != null){
 try {
  camera.setPreviewDisplay(surfaceHolder);
  camera.startPreview();
  previewing = true;
 } catch (IOException e) {
  // TODO Auto-generated catch block
  e.printStackTrace();
 }
}
}

@Override
public void surfaceCreated(SurfaceHolder holder) {
// TODO Auto-generated method stub
camera = Camera.open();
}

@Override
public void surfaceDestroyed(SurfaceHolder holder) {
// TODO Auto-generated method stub
camera.stopPreview();
camera.release();
camera = null;
previewing = false;
}
}

Download the files.

next:
- Add a overlay on Camera Preview SurfaceView